Sound amplifier



May 6 1924.l 1,492,889

A: K. MILLER SOUND AMPLIFIER Filed March 22. 1921 UNITED rvs-m-rs PATENT OFFICE.

A'Lrnnn x. or Los ANGELES, CALIFonNIA.

some1)` AMPLIFIER.

,Application mea :man 22, 1921. serial no. 454,534.

kin of sound producing apparatus, whether human i or artificial, and in connection with all various kinds of artificial vsound producing apparatus. In the particular 16 embodiment of the invention hereinafterv described and illustrated inthe accom anying drawings,`the sound amplifier iss own specificall adapted to be used in connection with a -p onogra'ph, but it will be' particularly understood that the invention yis not restrictedto such use, such particular application of the devicebeing only used 1n this specification as illustrative and for the qpurplose of making my invention clear'and B6 inte ap lication. l v

t is not only an object of my present invention yto provide a device [for amplifying sounds but also a device which will, in accomplishing its purpose of amplification, not introduce into the amplified sounds other sounds which are foreign to those received by the amplifier, andi which may be objec-y tionable. On the other hand, it is, in some instancesy at least, an object of the invention to rovide the device in such form that it wi (relativel eaking) qualify theamlified sounds iiysbringing out more strongy certain kinds of sounds not amplified in an ordinary amplifier or phonography horn, but` weakly amplified. andv are therefore comparatively lost or drowned' out in the larger amplification of' other sounds. The particular construction and design shown in the accompanying drawings and described hereinafter, is one which I have` found very effective for the clear amplification 'of vocal and instrumental sounds and tonesy of a phonogra h; amplifying those sounds and tones an at the same time keeping their igible by means of atypical specific,

natural and proper qualifications and eliminating a great many of the ^objectionable sounds an tones that are usually prevalent in phonographic reproductions. For instance, in phonographic reproductions, there is a distinct tonality usually due to the horn or amplier itself, and is one of the tonalitiesk that enters into that characteristic tonequality that is known as phonographicff My present sound amplifier does away with suchobjectionable tone"qualifi cations.

For the purpose of making my invention clear and intelligiblel will now proceed to a detailed and specific'description of one specific form of sound amplifier thatI have found successful in connection with phonograph machines, reference for this purpose ein had to the accompanying drawings, inw ich -Fig. 1 'is an elevation illustrating an arrangement of my sound amplifier with a phonograph machine; Fig. 2 is an enlarged longitudinal central vertical section of the sound amplifier; Fig. 3 is a front end elevationy of the same; Fig. 4 is a vertical section'taken as indicated by line 4 4 of Fig. 2; Fig.y 5 is'a plan of the amplifier; Fig. 6 is a section taken as indicated kby line 6 6 on Fig. 2; Fig. 7 is a section taken as 'indicatedby linev 7 7 on Fig.` 2; and Fig. 8 is a horizontal section taken as indicated by line 8 8 on Fig. 2. v n

`In the drawin sin Fig. 1 I indicate the elements of a p onograph machine, illustrating the table at`l0, a record at 11, a repro'ducer at R, a tone arm at 12, the rear end of whichconnects with an elbowy at 13, and to the lower end of this elbow 13 my sound amplifier A is connected. It makes no difference in what position the amplifier is placed; but I have shown it placed in such a position that it hangs below the elbow 13; and so shall describe its component parts in that'position. The inlet tube or throat of the amplifier isshown at 15, preferably circular and this opens into the amplifier proper as illustrated in the drawings. yImmediatel'Y under the entering tube 15 the back wal of the amplifier curves somewhat inwardly as illustrated at 16, so that the sound waves impinge upon this forwardly curved portion and are thrown outwardly toward the forward opening of the ainplifier. In the portion 16 a horizontal section of the wall becomes either flat or slightly convex, rather than concave as it is at other places. This condition is well illustrated in Figs. 5 and 8. From the portion 16 the back wall of the vamplifier curves downwardly and forwardly as illustrated at 17 and then somewhat upwardly and forwardly as shown at 18, to the mouth 19. Around the mouth 19 there may be (although I have found that thisis not necessary) an inwardly turned flange 2() which reduces the size of theniouthto a diameter substantially less than lthe diameter of the body of the amplifier directly back of the mouth opening.

The upper wall of the amplifier is a continuation of the forward wall of the tube 15, the .wall being curved forwardly and then upwardly as indicated at 21. Side walls as shown at 22 flare forwardly and outwardly toward the mouth. The vertical sections of Figs. 4, 6 and 7 sli ow the general circular or oval formation of the walls when looked at from the forward end.

Across the upper parts of kthe amplifier opening, and a little forward of a position directly below the forward wall of tube 15, there is a deflector wall 30, whose position and configuration are shown in the drawings. This deflector wall may preferably be made integrally with the body of the device and may preferably have a slightly forwardly curved lip 31 at its lower edge. lVall 8O extends in a curve across the interior of the structure, as it thus shown in Figs. 5 and 8, being concave inwardly and convex outwardly. Its upper edge joins the wall :21 at about the lowermost point of that wall 21; and the klower edge ofthe ydeflector walls 30 extends down to a point substantially opposite or perhaps a litt-le below, the upper part of the inwardly curved portion 16 of the back wall. The lower edge 31 of wall 30 stands substantially on the level, or perhaps a little above, the center of the opening 19.

The device which I have described resonates, qualifies, and augments sound waves by its peculiar conformation and not by virtue of any resonant qualities of its walls. It is not necessary, for its full and complete operation that the walls be made of any resonant or vibratory material. So, for the purposes of this device I may and do malte the whole device of some suitable material which will furnish a sound reflective surface rather than a sound resonating wall. For many purposes it is preferable to use such a material as I here designate, as thereby all foreign resoiiations from the walls of the of aluminum with comparatively thick and iion-vibratory walls, finishing the interior to a smooth surface.

`I have said that it is of no consequence in what relative position this sound amplifier is placed; in the precedin description I have, merely for ease of escription, explained the device in one particular position. For the purposes of the following claims, wherever for ,more specific setting out of the structure it is necessary to describe specific relations of parts, I shall consider the tube 15 to extend in a transverse direction and consider the opening 19 to face in a longitudinal direction; that is, for instance, Fig. 8 is a section on a plane which extends longitudinally from left to right in that li ure.

It will be understood however that the inventioiil in its broader aspects is not limited to the particular relative arrangements and combinations herein specifically shown as a. particular embodiment, except as specifically limited by the following claims.

Having described a preferred form of my invention, I claim:

1. A sound amplifier, comprising a hollow body with an inlet opening leading downwardly iiito the rear part of the body, an outlet opening at the forward end of the body yfacing iii a horizontal direction, and the wall of the body extending continuously and smoothly from the rear edge of the inlet opening first downwardly and then curving into a horizontal direction and then curving upwardly where it comes to the outlet opening, the body having an inwardly han ing flange around the outlet opening to re uce it in size as compared with the immediately adjacent part of the body interior.

2. A sound amplifier, comprising a hollow body wit-h an inlet tube extending downwardly into the rear part of the body.l having an outlet opening at its forward end facing in a horizontal direction and having continuous and smoothly extending walls leading from the walls of the inlet tube to the periphery of the outlet opening, the rear wall extending from the rear wall of the inlet tube on in a generally downward direction and bending forwardly and then bending upwardly to the lower edge of the out let opening, and the wal] leading to the upper edge of the outlet opening extending rearwardly and downwardly therefrom in back of the outlet opening and curving and joining the front wall of the inlet tube, and a downwardly extending deflector wall extending from said last mentioned wall nea-r the point where it joins said wall of the inlet tube and lying across the communicalos f facing in a. horizont tion of the inlet tube with the hollow interior of the body, said defiector wall being disposed at the rear of and opposite the outlet opening.

3. A sound amplifier, comprising a hollow body with an inlet tube extending downwardly into the rear part of the body having an outlet openin at its forwar end direction and having walls leading from the walls of the inlet tube to the periphery of the outlet opening, the rear wall extending from the rear wall of the inlet tube on in a generally downwardl direction and bendlng forwardly an then bending upwardly to the lower edge of the outlet openin and the wall lea ing to the opposite e ge of the outlet opening extending rearwardly and downwardly therefrom in back of the outlet openin and curving andjoining the front wally o the inlet tube, the first mentioned wall in its downward extent having a somewhat inwardly convexed portion.

4. A sound amplifier, comprising a hollow body with aninterior that expands from one end to the other and an outlet opening at its larger end, an inleto ening that leads transversely into the sma ler end rof the body at one end, the walls of the body extending continuously and smoothly from the inlet opening to the outlet o ening, and a defiector extending across the ody opening and projectin transversely from the body wall at that sige at which'the inlet leads in, said deflector being disposed op osite the outlet opening.

5. A sound amp ier, comprising a hollow body with an interior that expands from one end to the other and an outlet o ening at its larger end, an inlet opening t at leads transversely into the smaller end of the body at one end, and a defiector extending across the body opening and projecting transversel from the body wall at that slde at which the inlet leads in, said deiector having a forwardly curved lip along its lower edge.

6. A sound amplifier, comprising a hollow body with an interior that expands from one end to the other and with an outlet opening at its larger end, a transverse inlet tube opening into the interior of the hollow body at the small end thereof, the walls of the tube merging into the walls ofthe body, one of the body walls having a convexed portion so disposed with respect to the tube and outlet openin that sound waves entering the hollow bo y through the tube im inge the convex portion and are thereby de ected through the outlet o enin y 7. A sound amp ier, comprising a hollow body with an inlet tube extending downwardly into the rear part of the body, having an outlet openin at its forward end facin in a horizonta direction and having wa ls leading from the walls of the inlet tube to the periphery of the outlet opening, the rear wall extending from the rear wall of' the inlet tube on in a generally downward direction and bending forwardly and, then bending upwardly to the lower edge of the outlet openin and the wall leading to the opposite edge o the outlet opening extending rearwardly and downwardly therefrom in back of the-outlet openin and curving and joining the front wall o? the inlet tube, the first mentioned wall in its downward extent having a somewhat inwardly convexed portion opposite and directly facing the outlet opening.

8. A sound amplifier, comprising a hollow body with an inlettube extending downwardly into the rear part of the body, having an outlet opening at its forward end facing in a horizontal direct-ion and having walls leadin from the walls of the inlet tube to the perip ery of the outlet opening, the rear wall extending from .the rear wall of the inlet tube on in a generall downward direction and bending forwar ly and then bending upwardly to the lower edge of the outlet opening, and the wall leading to the opposite edge of the outlet openin extending rearwardly and downwardly t erefrom in back of the outlet opening and curving and joining the front wall of the inlet tube, the first mentioned wall in its downward extent having a portion convexed inwardly ,both in a horizontal and verticall plane.

9. A sound amplifier, comprising a hollow body with an inlet tube extending downwardly into the rear part of the body, having an outlet opening at its forward end facing in a horizontal direction and having walls leading from the walls of the inlet tube to the periphery of the outlet opening, the rear wall extending from the rear wall of the inlet tube on in a generall downward direction and bending forwar ly and then bending upwardly to the lower edge of the outlet opening, and the wall leading to the opposite edge of the outlet openin extending rearwardly and downwardly t erefrom in back of the outlet opening and curving and 'oining the front wall of the inlet tube, the rst mentioned wall in its downward extent having a somewhat inwardly convexed portion, and a defiector extending downwardly from the junction of the front wall of the inlet tube with the body wall which leads to said opposite edge of the outlet opening, said de ector depending to a point substantially opposite the upper extent of said convexed portion.

10. A sound amplifier, comprising a holllow body with an interior that expands from one end to the other and with an outlet opening at its larger end, a transverse inlet tube opening into the interior of the hollow body at the small end thereof, the walls of the tube merging into the Walls of the body, one of the body Walls having a convexed portion so disposed with respect to the tube that sound waves entering the hollow body through the tube inipinge und are deflected by the convex portion, und a defleotor extending doWn- Wurdly from the junction of one of the tube Walls with one of the body Walls, said deector depending to a point substantially opposite the upper extent of said oonvexed porl0 tion.

AIn witnessthat I claim the foregoing I have hereunto subscribed my name this 17th day of March, 1921.

VALFRED K. MILLER.

I/Vitness v VIRGINIA BERINGER. 

